Note: Previous versions of this document described an api-nonce value, which is a value that should increase
between the bounds of 0 and 253. This scheme is no longer supported. It has significant problems with multithreaded
clients and should not be used. Do not use it for new applications.

The data part of the HMAC construction should be exactly equal to the raw body you send to the server. You can send
JSON or form encoding, just ensure you use the exact same body string in the HMAC. Generally you will want to prepare
the request in your language of choice, then use the same raw body string for the HMAC construction as in the
request body.

If you are receiving "Signature Not Valid" messages, check the following:

Check that your signatures match the sample signatures above.

If there is a request body, make sure your Content-Length and Content-Type are valid.

Ensure your request body is being properly sent. Try a few sample requests against httpbin.

Ensure you are signing the exact string that is being sent to the server. Certain JSON serializers have
unstable key ordering, so serialize to a string first, sign that string, and then send the same string in the request
body.